1. Field of the Invention
The present invention relates to gear retainer means and more specifically to mainshaft gear retainer means for a transmission having a plurality of substantially identical countershafts and at least one pair of closely axially spaced radially floating mainshaft gears.
2. Description of the Prior Art
Gear retainer means for pairs of closely spaced and radially floating mainshaft gears are known. The prior art devices usually utilized retainer means associated with one of the two closely spaced gears to prevent axial movement of that gear in one direction, movement of that gear in the other direction is prevented by the other gear and its associated retainer and vice versa. When the forces tending to move one of the gears are reacted by the other gear and its associated retainer, the forces must cross retainer surfaces rotating at different speeds; this makes the retainer subject to wear and failure.
An improved gear retainer means for pairs of closely spaced and radially floating mainshaft gears is disclosed in U.S. Pat. No. 4,034,620, assigned to the assignee of this invention and hereby incorporated by reference. This disclosed improved gear retainer means utilizes structure whereby the axial forces tending to move one of the closely spaced mainshaft gears relative to the other mainshaft gear cross reaction surfaces which are rotating at the same speed, namely the speed of the mainshaft gear which is clutched to the mainshaft. While this disclosed structure is highly desirable as it tends to minimize wear and failure of the reaction surfaces, this disclosed structure is not entirely satisfactory as the design utilized a somewhat complicated and expensive to manufacture thrust member and additionally the two closely spaced mainshaft gears are interlocked in a manner making later disassembly thereof difficult and/or impossible.